Solutions comprising a glycopeptide antibiotic, for example Vancomycin, and an amino acid or amino acid derivative such as an N-acetyl amino acid are provided. These solutions are stable or stabilized for long-term periods at conditions of normal use and storage, and can be formulated as pharmaceutical solutions for use in subjects. Methods of manufacturing and using these solutions are also provided, as are methods of stabilizing a glycopeptide antibiotic, for example Vancomycin, using amino acids or amino acid derivatives such as N-acetyl amino acids.